This invention relates to a control device for a vending machine and the like apparatus operating responsive to deposition of a coin or a bill and a method for sending and receiving information in such device.
Control devices for a typical vending machine generally consist of a section which is mounted on the side of a coin mechanism (hereinafter referred to as a "coinmech control section") and a section which is mounted on the side of a vending machine proper (hereinafter referred to as a "vendor control section"). The vendor control section is constructed so as to be adapted to the purpose of the vending machine whereas the coinmech control section is constructed so as to be adapted to the coin mechanism and the construction of the vendor control section combined with the coin mechanism.
The coinmech control section generally has functions including a function of counting the amount of deposited money in response to a signal from a coin switch and judging whether vending is possible or not upon comparing the amount of deposited money with a set vend price, a function of subtracting the set vend price from the amount of deposited money when vending has been made and paying out change upon completion of the vending operation. The vendor control section has functions including a function of sending a set vend price signal to the coinmech control section when necessary, a function of controlling dispensing of a selected article when the judgement that vending is possible has been made, a function of supplying a money collection signal or a change payout signal to the coinmech control section and other special functions depending upon the use or purpose of the vending machine.
Operations in the coinmech control section and the vendor control section have a somewhat random aspect in that one control section cannot estimate the operation of the other control section timewise accurately and hence it is necessary in the prior art vending machine to construct the two control sections in such a manner that while they are performing their operations independently and sending their output signals to each other independently from each other, they keep incessant watch on states of input signals from their counterpart control section which are timewise unexpectable. For example, the time when a coin is deposited in the vending machine (i.e., when a coin deposition signal is supplied from the coinmech control section to the vendor control section) is quite unexpectable. A similar situation exists for other signals. For this reason, the signal transmission between the two control sections has previously had to be made in a parallel processing resulting in provision of an enormous number of wirings. Even if a time-division serial processing is employed, the prior art machine in which the two control sections must constantly watch the signal states of each other requires high speed in the scanning cycle with resulting difficulty in the circuit construction or the design of the scanning program.
A further problem arises in making a universal type of coin mechanism which has recently been attempted from the standpoints of productivity and economy. For making a universal type of coin mechanism, the coin mechanism must be constructed such that it will be adapted to all uses and functions and, for this purpose, necessary numbers of switches and relating circuits corresponding to such uses and functions must be provided. Special functions to be provided in the coin mechanism side for realizing the universal type of coin mechanism include (1) single vending-plural vending switching, (2) restriction on the number of successive vending, (3) successive vending timer, (4) minimum set price, (5) total sales price display, (6) vend test time price display, (7) vend test and (8) intermittent display at the time of malfunction and malfunction display. Switches and relating circuits corresponding to these functions therefore are required. Since the size of the coin mechanism is limited, there is physical and economic difficulty in mounting all of the switches and circuits relating to these special functions in the coin mechanism. For example, a common layout of ten numerical keys which are inexpensive but bulky cannot be used because of the insufficiency of space. In addition, compact but expensive switches must be individually provided such that the device is uneconomical. There is a case in which the common ten numerical keys can be used, however. In this case, a back-up circuit for the stoppage of electricity in a memory storing ten numerical key input data or a nonvolatile memory must be provided resulting in an increase in the cost. In addition, numerical keys for setting data and a back-up circuit for stoppage of electricity must be provided on the vendor control section side also and such provision of the same components in the two control sections is disadvantageous from the standpoint of the cost. Besides, there are very few types of vending machine which use all of the special functions provided on the side of the coinmech control section for making the universal type vending machine and some of these functions are found unnecessary and simply wasted depending upon the type and use of the vending machine.
There is a prior art vending machine of a type in which, for the purpose of making a universal type of vending machine, main functions of the coinmech control section, i.e., counting, comparison and other operation functions, are removed and switches, motors and solenoids only are retained. In this type of vending machine, however, substantial control and operation functions are all dependent upon the vendor control section so that switches, a change payout motor and a CREM solenoid must be connected to the vendor control section by independent wirings resulting in increase in the number of wirings between the coinmech control section and the vendor control section. Further, the vendor control section must constantly watch a number of switch output signals provided from the coin mechanism side whereby difficulty arises in the circuit design. For example, state of the coin switch output signal must constantly be watched. During paying out of change, states of output signals of a motor carrier switch and a coin confirmation switch must constantly be watched. It is a tremendous load to the vendor control section to watch states of output signals of the coin mechanism side and control necessary operations such as money amount counting in accordance with results of watching while controlling operations relating to aritcle selection and vending. In a system employing a microcomputer, a scanning program must be prepared so as not to overlook an instantaneous change in the switch output signal, which places a heavy burden on the preparation of the program and the design of a program ROM. Furthermore, the necessity for detecting an instantaneous signal change on the side of the coin mechanism tends to cause an error due to insufficient connection of a connector.